Improvement in pendulum-levels



Wz'fn ea.: e,

/mzw,

I. S. WINTER. Pendulum-Level.

Patented Nov. 4,'1879.

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH G.

UNITED TA'rs FFIOE.

IGNATIUS S. VVINTER, OF BOSTON, lllASSAGElUSETTS, ASSIGNOR OF ONF- HALF OF HIS RIGHT TO ARBEE G. HYDE, OF SAME PLACE.

IMPROVEMENT IN PENDULUM-LEVELS.

Specification forming part of Letters Patcnt No. 221.350. dated November 4, 1879; application filed August 7, 1879.

To all fwhom it may conccm:

Be it known that I, IGNATIUs S. WINTER, of Boston, in the county of Suftblk and State of Massachusetts, have invented certain Improvements in Phnnb-Levels, of which the following is a speeitication.

This inventon relates to pluinb-levels, or thoscin which apivoted penduluin or weighted finger is substitnted for a glass tnbe containing alcohol and air.

The object of the invention is to provide certain il'nprovements in the construction of a plumb-level, whereby its accuracy, convenience, and durability are incrcased.

To these ends my invention consists in the improvements which I will now proceed to describe and claim.

Of the accompanying drawings, forming a part of this specification, Figure 1 represents a side elevation of a pluinb-level embodying my' invention. Figs. 2 and 3 represent, respectively, sections on lines .mc andy y, Fig. 4, which represents the end of the level-stock.

Similar let-ters of refercnce refer to like parts in all the figures.

In the drawings, a reprcscnts a level-stock, of the usual form and of any suitable material, preferably wood. In the center of the stock is formed a transverse aperture extending entirely through the stock. This aperturc is preferably formed by horing through the stock, and is preferably countersunk or .enlarged at its outer ends to form shoulders or bearings c c.

d d represent two glass plates which rest on the shoulders c c, and entirely cover the ends of the aperture, and convert the latter into a close chamber with transparent sides. The pla-tes d (Z are parallel with each other, and are seeured to the stock by metallic marginal frames f f, which are serewed to the sidcs of the stock and project over the margins of the plates. To secure the parallelism of the plates d d, I prefer to interpose between them a metallic ring or short eylinder, q, which forlns a lining for the aperture. The ends of therin g are parallel and pro] ect slightly beyond the shoulders c c, and form hearings for the inner sides of the plates d, said plates being pressed closely against the ends of the ring by the frames ff.

By the described construction a glass-Sided ehamher is formed in the stock, the contents ot' which can be l'reely viewed from either side of the stock.

hreprcsents the pendulum or weightcd finger, which is conlposed of a weight, 1, preferably scinicircular, and fin gers 2, projecting upwardly from the weight, and arranged to assnme a vertical position when the weight is at rest. The pendulum h is provided with trunnions t i, projecting from opposite Sides thereof, the weight being mainly on one side of the line of the trunnions.

The glass plates d are provided on their inner sides with sockets, which receive the trunnions i i, as shown, and permit the pendulum to rotate or vibrate freely, the pendulum be ing insertcd in the chamber before both of the glass plates are applied thereto. The sockets in the glass platcs form hard, smooth, and durable bearings for the trunnions of the pendnlum, enabling the latter to rotate or vibrate with the least possible friction, and being so hard that they will endure very protracted use without'being worn enough to interferewith the Operation of the pendulum.

lt will be seen that the glass plates notonly support the pendulum on both sides, but also protect it from dust, dirt, and moistnre, and enable it to be viewed from either side of the stock. The platesf are provided With four lnarks, i' i' 17 fi', arranged to divide a cirele into four equal parts, and indicate, in connection with the pendulum, When the stock is in a horizontal or vertical position. The level is thus adaptcd to be used with either edge or end uppermost, as will be readily seen.

\'Vhcn the stock is moved suddenly, so as to cause the pendulum to rotate rapidly, it is desirable to arrest' the Vibrations, so that the pendulum will come quickly to its point of rest. To this end I provide the pendulum with a continuous circular rim,j, which is rigidly attached thereto and is concentrie with the axia-l line of the pendulum. I provide the stock with a brake, k, adapted to be hrought in contact with the rim whenever the operator desires to arrest the Vibrations of `the pendulum. Said brake is provided with a spring, s, to withdraw it from contact With the rim j, and with any suitable means to enable the operator to push it against said rini.

The brake is preferably a rod or pin adapted to slide in an Opening in the stock, and provided with a head, k', which has two inelines on one side, as shown in Fig. 3.

The means for pushing the brake against the rim are preferably two wedges, ll, adapted to slide crosswise ot' the line of inotion of the brake and bearing upon the inelines of the head k'. The wedges have lieads l/ l', which project through the sides of the stock and enable the wedges to be pnshed in by the operator. When either or both of the wedges are pushed in they force the brake against the rim, and when said wedges are released the Spring s forces the brake and wedges outwardly.

By the employment of the continuous rim j and the brake I am enabled at any time to stop the motion of the pendulum, regardless of the position of the stock.

It will be noticed that this level has no arbitrary base, and that it can be used eorreetly with any of its edges as a base, the finger indicating with equal exactuess in a vertical, horizontal, or intermediate position the level or plane as truly as if an arbitrary base were used.

I claim as my invention- 1. A plumb-level having an apertured stock, by whieh the indicatious may be read from both sides thereof, and a weighted index suspended between and supported in soekets in glass sides, in combination with such glass sides inelosin g the apertnre and forminga (lusttight chamber thereof, suhstantially as shown and described.

2. The combination of an apertnred levelstock, a lining for such apertnre, having parallel edges, glass sides to such aperture, retained in parallelism by such lining and exterior confining-plates, and an index or finger suspended between the glass plates, substantally as shown and described.

3. A level having a snspended weighted index or indieating-finger, in combination with a .Spring-brake and transversely-moving mechanism aeting upon said brake to impart to it longitudinal movement, substautially as and for the purpose described.

In testinony whereof I have signed my name to this specifieation in the presenee of two snbscribing witnesses this 4th day of Angust, 1879.

IGNATIUS S. WINTER. Witnesses:

U. F. BROWN, (leo. W. PIERCE. 

